Measuring instrument.



The object ofthis 'Amixnnnnnnwnn- 'or LONDON, iiiiermiivp', Assienon gro ivinnenitwf nELEss Yr TELEGRAPH'COMPANY OF AMERICA, or NEwYoRK; N". Y., vn' oonronATjioitonnEtt' .Ei'wf'EN, 5 subject 'l of, ythe King of Great Britain, lresiding at Marconi House, Strand, London, .England. have invented new and fuseful Improvements in Measuringlnstruments,-of which the folloiiing-isa speciiication. f

invention is to provi-de an instrument lin which4 the effect of small extensions-,or contractionsoifl a filament,- or

' of exteii'al stresses applied-to the filament, 'may b'e'niultiplied'fortlie purpose' of measuring the amount 4ofthe extension or contraction, or the strength of the applied s 'tressso v as to' gixe a measure thereof. Y,

. Accordingtothis invention an arm or inf.

dicator" so "mounted that'the only movement" Whiehi capable 1s rotation in one planej l .around anl 'isand subject to. a controlling to' oneQendOi end of 'Which` isr c Such an instrument may beusedt'o indil cate the contraction, expansion. or tempera'- ture ofv-the ilamer'it4 or filaments,y or the strength of an Ielectric `current fi'owing- .through the filament or filaments.

Theinvention' is illustrated by the accompanying' dralwin'gs whicl' show var/ions forms of measuring instrumen Figure 1' yshows the simplest form.

Fig. 2 shows an .instrument'simiiiar to Fig.

' instrument, in its 'l except that there are two lWires -.connected lto the arm on opposite sides4 of'the axis.

Fig. 3 shows' afurther; modification Witheight wires so arranged that fthe lcurrent sses throughthem in'parallel and noii zfinductively.- f .l

Fig. ishows an 4instrument in Whichl 'the l.

Support' to lWhich the' ilainentsare connected is. movable and a'c'tsas'the arma-ture of an, electiofmagnet. A. L

Fig. '5, showsA a. modi'catilon ,of theinstru- 4ment shown in Fig.. 4., j v l In Fig. 1l A is an indicator arm having an arbor mounted in agfraine C to which is. secured one end of a. spring D, the other' end j ofwhich is securedto the armA. -isfa Fig. 3 shows iviniisnnine' INSTRIMENT.

-'Sp'eci'cat1on of Iiefttersvatent. :Ilgltiglted Mdr, 19j 2^; `,App1iaii. iea septeniier 3o, 1916. serial-N0. isaiasi.

vconnected to the' arin While the other iS connected to. a fixed support F; iThe "ar-l rangement lis such that the'wltension of the, wire tends'- to bring the indicator into the position in Which-the point of attachment of turn the arni away 4from that positionf Then the-ref'oi'ean electric current is'passed l ig.' 2 shows an instrument similar .to Fig.

l except that" there are two'V wiies,c'oniiecte d to the' arm on opposite'sldes of the axis.1

eightivires so arranged `that 4the 4currei'it 4,pa'sses. 'through them inpaiallelwand nonindjuctively.

Fig. i lshow-s supports F. are

such construction, the tension of the filamentor conductor E and therefore the.posi tion of v`the indicator arm `will bev controlled not. onlyzby the st ren'gthV vofthe current car- ,ried by the conductor, but also by-the position of the support F.4 Since the position ofthe support .F. is in tnrnv controlled by the strength of the current passing through the electromagnet H, the position of the arm` A will indicate the combined result ofthe in the -electroinagnet'I-I. Fig. 5 shows. an` instrument in which the current in' the conductor,E andthe current l 'electrostatic force ,between lthe .plate Gand of the electroa-plate H is'employed instead magnetic force of Figffi. l

What I claim is :'--l 'l 1. in 'measuring instrument, the. combination of a frame, an arbor rotatably mountan instrument in" which vthe 1 mounted on a plate-.G slid.- I 'ably mounted on the frame and acting as lthe armature'of an. electro-magnet H. 'iVith 'the'filanient to the'arin 'is as near as possible.' Ato the support F, while the springften'dfs to',

a further-modification' withl I ed therein, an arm fast on the arbor, means for applying to the arm a force ,tending to rotate 'the arbor, a, support carried by 'the 'frame andA capable ,of 'vmovingf'upon the iframe parallelto the' axis of Ithe arbor, means for. applying to' 4the support a force'v `tending to moveit and' a stretched ex-4 'pa'nsibleQ-iilament 'connected' at lone lend tov the arm andati-'the other end to the support.

55 ,metal :filament onf- Wire qnaie'ndgvo'girhch i. '22g-In @measuring instrument, theI ombiframe parallel to the axis of the arbor,

means for applying to the support a force tending to move it and a plurality of stretched expansible filaments each connectl ed at oneJ end to the arm and at the other endy t-o the support.

3. An instrument for-measuring electrlo currents, compr1s1ng. a frame, a member rotatably mounted thereon, resilient means tending to rotate said member, a supportslidably mounted on the frame, an expansible conductor connecting-the member and the support, the tension ofsaid conductor acting in opposition to said resilient means and being controlled by the strength of the current carried by the conductor and b v the position'of the support to determine the position of said rotary member, and means controlled by an electric current for determining the position of said support.

HAERY ALEXANDER EWEN. 

